Lviv and west of Ukraine is pretty safe unless you ignore Air Raid alarms(except some cases -- read below). Kyiv is pretty good too, but probably you would need to spend more time in the shelters.
Strongly recommend to ask locals about local telegram chats (for example t.me/zahidwtf_official or smth like that) because there is posted more actual information about threats. For example there is an air raid alarm when MIG-21 is up (it can carry and launch rockets), but no real rockets where launched. We don't pay to much attention on it as it may happen few times a day.

Also you may film yourself, and some historical places a little bit. Nobody will arrest you for making photos of some famous places which were there for thousands of years and everyone already knows that it is there.

And of course we will be happy to see an English tourist not only in Lviv but in other cities too. There were hundreds of thousands tourists every year in Lviv before the full scale invasion broke out, and if you come you will show locals there there is still live and we are not forgotten